Study Questions:

Have risks of major amputation and death associated with leg revascularization procedures changed over the past decade?

Methods:

A total of 103,934 patients who underwent endovascular (angioplasty) or surgical
(endarterectomy, profundaplasty, or bypass) lower limb revascularization for infrainguinal peripheral artery disease (PAD) in England between January 2006 and December 2015, were identified from individual Hospital Episode Statistics (HES) records. Death and adverse events were identified from HES and Office for National Statistics mortality records. Competing risk regression was used to estimate cumulative incidence of major amputation and death adjusting for disease severity, comorbidity, and demographic risk factors.

Results:

Estimated 1-year risk of major amputation decreased from 5.7% (in 2006-2007) to 3.9% (in 2014-2015) following endovascular and from 11.2% (2006-2007) to 6.6% (2014-2015) following surgical procedures. Risk of death after both types of revascularization also decreased. The largest decreases were observed in patients with severe ischemia based on presence of ulcer or gangrene. These trends were observed despite an increase in morbidity during the study period. Use of endovascular procedures expanded for severe PAD over the study period.

Conclusions:

Overall survival increased and risk of major lower limb amputation decreased following revascularization. These observations suggest that outcomes after lower limb revascularization have improved during a period of centralization and specialization of vascular services in the United Kingdom.

Perspective:

This analysis suggests that adverse events have decreased over the past decade in the United Kingdom despite increases in age, comorbidity, and prevalence of severe ischemia among patients undergoing lower extremity revascularization procedures. The greatest reductions in risk of death during the study period were observed among patients with critical limb ischemia. Considering that expected mortality is significantly higher for critical ischemia compared with claudication, patients within this subgroup might therefore have a correspondingly greater potential for risk reduction. Lower amputation rates might also be expected among claudicants, who do not necessarily progress to critical limb ischemia when patency is lost.

The authors attributed these improvements in lower extremity revascularization outcomes to a reconfiguration in vascular services that occurred in the United Kingdom during the latter part of the study period, which included centralization of arterial surgery (including bypasses and amputations) to high-volume hospitals (defined as providing a vascular on-call rotation >1:6 and serving a population base of 800,000 or more). Unfortunately, provider and hospital-level effects were not included as variables in the competing risk regression model, so this conclusion is not directly supported by the data. Nonetheless, these results support the notion that specialty care from providers who perform a greater volume of complex procedures improves outcomes, and the UK criteria for these designations could serve as an example for other health systems. Increased utilization of endovascular procedures for critical ischemia during the latter portion of the study period also may correspond with more advanced endovascular capabilities at higher volume centers, making the reduction in adverse events associated with surgical revascularization even more impressive given that these centers likely used surgery more selectively (and for more anatomically challenging disease).